Question Detail
Question
Find ∫(5x)/(x²+6x-7) dx
Correct Answer
Option B is the correct answer.
Detailed Explanation
This integral can be solved using partial fraction decomposition.1. Factor the denominator: x² + 6x - 7 = (x - 1)(x + 7).2. Set up the partial fraction decomposition: 5x / [(x - 1)(x + 7)] = A/(x - 1) + B/(x + 7)3. Multiply by the common denominator to clear fractions: 5x = A(x + 7) + B(x - 1)4. Solve for A and B: * Set x = 1: 5(1) = A(1 + 7) + B(0) => 5 = 8A => A = 5/8 * Set x = -7: 5(-7) = A(0) + B(-7 - 1) => -35 = -8B => B = 35/85. Substitute A and B back into the integral: ∫ [5/(8(x - 1)) + 35/(8(x + 7))] dx6. Integrate term by term: = (5/8) ∫ (1/(x - 1)) dx + (35/8) ∫ (1/(x + 7)) dx = (5/8)ln|x - 1| + (35/8)ln|x + 7| + COptions A and B are identical and match this result. Since B is marked, we choose B.
Hint
Start by factoring the quadratic denominator. Then use partial fraction decomposition to break down the rational function into simpler terms that can be integrated using logarithms. Remember to solve for the constants A and B.